SRPS IEC 60781:1996

Application guide for calculation of short-circuit currents in low-voltage radial systems

Scope

This application guide presents a practical method to be used when calculating short-circuit currents in low-voltage networks. The method corresponds strictly with HD 533 and leads to conservative results with sufficient accuracy. Two short-circuit currents which differ in magnitude are to be calculated: -the maximum short-circuit current which causes the maximum thermal and electromagnetic effects on electrical equipment and determines the required capacity or rating; -the minimum short-circuit current which may be a basis for the adjustment of protective devices.